MOSFET switching arrangement in a power converter unit

Abstract

A power converter unit includes a pair of switching DC/DC converter secti for positive and negative voltages which incorporate a MOSFET switching arrangement in which a pair of MOSFETs are forced to share the output load current equally, a current limiting arrangement which activates shutdown whenever the current threshold limit is exceeded, and an internal grounding arrangement which minimizes output of current spikes by isolating the switching spikes from the input and output.

What is claimed: 
     
       1. A MOSFET switching arrangement in a switching DC/DC converter, comprising: (a) a pair of MOSFETs connected in parallel between an input and an output of the converter;   (b) a drive circuit having first and second portions connected in parallel with one another and in series with said MOSFETs for driving said MOSFETs; and   (c) means for generating an AC signal, each of said respective first and second drive circuit portions including serially-arranged current flow control means and drive circuit switching means connected between said AC signal generating means and said MOSFETs for respectively permitting current flow in one direction only from said AC signal generating means to said MOSFETs and alternately driving of said MOSFETs in a coordinated fashion such that when one of said MOSFETs is turned on, closing a conductive path between the input and output of the converter, the other of said MOSFETs is turned off, opening the conductive path.   
     
     
       2. The arrangement of claim 1 wherein said drive circuit switching means in each of said respective first and second drive circuit portions are operable for causing substantially instantaneous turn-on and turn-off of said MOSFETs. 
     
     
       3. The arrangement of claim 2 wherein said turn-on means is a capacitor and resistor network. 
     
     
       4. The arrangement of claim 2 wherein said turn-off means is a transistor. 
     
     
       5. The arrangement of claim 1 wherein said signal generating means includes: a pulse-width modulator circuit; and a transformer connected between said pulse-width modulator circuit and said current flow control means of said first and second drive circuit portions.   
     
     
       6. The arrangement of claim 5 wherein said current flow control means is a diode. 
     
     
       7. In a switching DC/DC converter section of a power converter unit for converting an unregulated DC voltage input to a regulated DC voltage output, a MOSFET switching arrangement, comprising: (a) a pair of MOSFETs having respective gate, drain, and source terminals, said respective drain and source terminals being connected in parallel between the input and output of the converter section;   (b) a drive circuit having first and second portions connected in parallel with one another and in series with said gate terminals of said MOSFETs for driving said MOSFETs; and   (c) means for generating an AC signal, each of said respective first and second drive circuit portions including current flow control means connected between said AC signal generating means and said respective gate terminals of said MOSFETs for permitting current flow in one direction only from said AC signal generating means to said MOSFETs so as to drive said MOSFETs in alternating fashion;   (d) each of said respective first and second drive circuit portions further including means connected in series between said MOSFETs and said current flow control means for causing substantially instantaneous turn-on and turn-off of said MOSFETs in coordination with said alternating driving of said MOSFETs.   
     
     
       8. The arrangement of claim 7 wherein said turn-on means is a capacitor and resistor network. 
     
     
       9. The arrangement of claim 7 wherein said turn-off means is a transistor. 
     
     
       10. The arrangement of claim 7 wherein said signal generating means includes: a pulse-width modulator circuit; and   a transformer connected between said pulse-width modulator circuit and said current flow control means of said first and second drive circuit portions.   
     
     
       11. The arrangement of claim 10 wherein said current flow control means is a diode.